Last Sunday evening, Fr Paddy O'Kane heard about the awful tragedy at Buncrana pier – and said a prayer for the poor priest who would have to officiate at the funerals. He did not know that he would be the one who would have to speak the Lord into the cold dark waters of awful grief that have affected so many people in this city and far beyond.

Ministry in this or any other society puts enormous pressure on the individuals who have to respond. They have to handle unspeakable grief and anger – and know how to celebrate the joys of being human. They have to know when to speak words into the pain and when to recognise that helpless silence speaks louder than words. They have much in common with other emergency services who work with such heart and generosity. But they are not just offering medical or rescue services in terrible situations. They also have to craft words when words seem inadequate – and to bear people's burdens with them. This is a vocation to stand in the breach between the solid ground of common sense and hope of the Promised Land on the other side of the desert. And, in this, they are nourished, challenged and supported by the faith communities from which they sprang and of which they are a part.

Last weekend we celebrated the feasts of Saints Patrick and Joseph. And it seems to me that these two great figures from our story might give some insight into all forms of vocation and specifically into the priestly calling, the establishment of which we celebrate on Holy Thursday.

Firstly, for our two saints, their calls meant a break with their plans. It was an insistent voice that said, "Forget your dreams, I need you for other tasks." Human brutality dragged the young Patrick from his home – and it was in his desert rather than in the land of his dreams that he met the God of his fathers. Joseph had his life arranged for himself and Mary – but God intervened with apparent lack of common sense. Take this pregnant girl to be your wife – and the child will not be the fruit of betrayal but an unimaginable grace.

Vocation to priesthood or consecrated life today is not sensible for many people. But God still calls individuals to leave behind their own plans and put themselves at the service of generous ministry, fruitful consecrated life and dedicated ministry in Jesus' name. Vocation is a call to serve God's dream not mine. It is a call to feed God's flock and not merely to nourish our own egos. It means ensuring that people see Jesus, the face of the Father's mercy and not just my face. But it comes with the reassurance that I will be most myself when I try to follow the often strange ways of the Creator. Brothers in the ministry, put yourselves at the service of Christ. Resist the temptation to fit Christ's ministry around your dreams.

Secondly, faithfulness to the still small voice calling in the night needs a deep spiritual life. God does not just ask people to do jobs for him and then go back to their comfortable personal lives. We will not hear the promptings of the Spirit unless we make space for grace. Prayer – individual, communal, aloud or in silent tears – is essential for those who wish to act in Jesus' name. We are his ministers, not his civil servants. As Patrick and Joseph discovered this is not a 9-5 job, anymore than being a parent or looking after a sick relative is regulated by the European Working Time Directive. The workers in the vineyard will bear fruit only if they know the Lord of the harvest. It is only a person of deep prayer who will be able to continue believing that the promises made to him or her by the Lord will be fulfilled.

Thirdly, St Joseph and Mary were entrusted with the little baby. They had to walk with that child believing what no-one in their right mind could see. But God, Emmanuel, is entrusted to weak people. We are earthenware vessels that bear such a rich treasure (2 Cor 4:7). But those bodies – which are made from the dust of the earth and which will return there - are reborn through the Spirit when water in poured over us in the name of the Trinity. Our bodies are anointed at Baptism, Confirmation, Ordination and in the Sacrament of the Sick. We are nourished with the Body and Blood of Christ. Our bodies are Temples of the Holy Spirit to be raised up on the Last Day. Our deacon in the diocese is Christopher McDermott and, please God, he will be ordained to priesthood in June. But the name Christopher means 'bearer of Christ' – and we, in our frailty, are all called to be that. Those in ordained ministry have a special vocation to bear Christ to his people in their hungers and their pains, their joys and blessings. We offer to God's people, not ourselves but the Christ whom we have been anointed to bear. It is a vocation to make ourselves decrease so that Christ can increase.

Finally, Patrick and Joseph will certainly have been mocked for their silly decisions and their unreasonable faithfulness. Jesus will be mocked tomorrow as he hangs helpless on the folly of the Cross. Those who sow in Jesus' name do not work so that they will see their successes. They work, knowing that one sows and another waters but that it is the Lord alone who gives the growth (1 Cor 3:7). In this springtime of the Church, we break up the hard ground and remove the weeds, we sow and nurture. But we may not see any of the fruit of our labours. However, if we do not sow today, there will be no fruit to harvest – and the Lord will find others who can be invited to the marriage feast of the Lamb, others will be called who will hear the words, 'come you blessed of my Father'. (Matthew 25:34). If we claim to follow in the steps of Patrick and Joseph, we work for God's glory not our satisfaction. We work according to a divine time-line, not on the basis of glory in my time.

This evening, we begin our three days of solemn celebration of the Lord's passion and Death – Holy Thursday, Good Friday and Holy Saturday. The last of those three days has been cut off by some and been re-named Easter Saturday. For many of our fellow citizens, Friday is good merely because it marks the beginning of the Spring Bank Holiday weekend. But we are invited to sit with the Lord this evening at the table of the last Supper, to stand speechless before the brutality and senselessness of the cross and to taste the bitter herbs of Saturday's emptiness before we celebrate the light that bursts out in the darkness at the Easter Vigil.

Only then can we all, made into a line of kings and priests to serve our God and Father, celebrate the Rising that makes all things new – and that will make sense, even of the tragic funerals that we will celebrate this afternoon.